net/rose/rose_timer.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *
   4  * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
   5  * Copyright (C) 2002 Ralf Baechle DO1GRB (ralf@gnu.org)
   6  */
   7 #include <linux/errno.h>
   8 #include <linux/types.h>
   9 #include <linux/socket.h>
  10 #include <linux/in.h>
  11 #include <linux/kernel.h>
  12 #include <linux/jiffies.h>
  13 #include <linux/timer.h>
  14 #include <linux/string.h>
  15 #include <linux/sockios.h>
  16 #include <linux/net.h>
  17 #include <net/ax25.h>
  18 #include <linux/inet.h>
  19 #include <linux/netdevice.h>
  20 #include <linux/skbuff.h>
  21 #include <net/sock.h>
  22 #include <net/tcp_states.h>
  23 #include <linux/fcntl.h>
  24 #include <linux/mm.h>
  25 #include <linux/interrupt.h>
  26 #include <net/rose.h>
  27
  28 static void rose_heartbeat_expiry(struct timer_list *t);
  29 static void rose_timer_expiry(struct timer_list *);
  30 static void rose_idletimer_expiry(struct timer_list *);
  31
  32 void rose_start_heartbeat(struct sock *sk)
  33 {
  34         sk_stop_timer(sk, &sk->sk_timer);
  35
  36         sk->sk_timer.function = rose_heartbeat_expiry;
  37         sk->sk_timer.expires  = jiffies + 5 * HZ;
  38
  39         sk_reset_timer(sk, &sk->sk_timer, sk->sk_timer.expires);
  40 }
  41
  42 void rose_start_t1timer(struct sock *sk)
  43 {
  44         struct rose_sock *rose = rose_sk(sk);
  45
  46         sk_stop_timer(sk, &rose->timer);
  47
  48         rose->timer.function = rose_timer_expiry;
  49         rose->timer.expires  = jiffies + rose->t1;
  50
  51         sk_reset_timer(sk, &rose->timer, rose->timer.expires);
  52 }
  53
  54 void rose_start_t2timer(struct sock *sk)
  55 {
  56         struct rose_sock *rose = rose_sk(sk);
  57
  58         sk_stop_timer(sk, &rose->timer);
  59
  60         rose->timer.function = rose_timer_expiry;
  61         rose->timer.expires  = jiffies + rose->t2;
  62
  63         sk_reset_timer(sk, &rose->timer, rose->timer.expires);
  64 }
  65
  66 void rose_start_t3timer(struct sock *sk)
  67 {
  68         struct rose_sock *rose = rose_sk(sk);
  69
  70         sk_stop_timer(sk, &rose->timer);
  71
  72         rose->timer.function = rose_timer_expiry;
  73         rose->timer.expires  = jiffies + rose->t3;
  74
  75         sk_reset_timer(sk, &rose->timer, rose->timer.expires);
  76 }
  77
  78 void rose_start_hbtimer(struct sock *sk)
  79 {
  80         struct rose_sock *rose = rose_sk(sk);
  81
  82         sk_stop_timer(sk, &rose->timer);
  83
  84         rose->timer.function = rose_timer_expiry;
  85         rose->timer.expires  = jiffies + rose->hb;
  86
  87         sk_reset_timer(sk, &rose->timer, rose->timer.expires);
  88 }
  89
  90 void rose_start_idletimer(struct sock *sk)
  91 {
  92         struct rose_sock *rose = rose_sk(sk);
  93
  94         sk_stop_timer(sk, &rose->idletimer);
  95
  96         if (rose->idle > 0) {
  97                 rose->idletimer.function = rose_idletimer_expiry;
  98                 rose->idletimer.expires  = jiffies + rose->idle;
  99
 100                 sk_reset_timer(sk, &rose->idletimer, rose->idletimer.expires);
 101         }
 102 }
 103
 104 void rose_stop_heartbeat(struct sock *sk)
 105 {
 106         sk_stop_timer(sk, &sk->sk_timer);
 107 }
 108
 109 void rose_stop_timer(struct sock *sk)
 110 {
 111         sk_stop_timer(sk, &rose_sk(sk)->timer);
 112 }
 113
 114 void rose_stop_idletimer(struct sock *sk)
 115 {
 116         sk_stop_timer(sk, &rose_sk(sk)->idletimer);
 117 }
 118
 119 static void rose_heartbeat_expiry(struct timer_list *t)
 120 {
 121         struct sock *sk = from_timer(sk, t, sk_timer);
 122         struct rose_sock *rose = rose_sk(sk);
 123
 124         bh_lock_sock(sk);
 125         switch (rose->state) {
 126         case ROSE_STATE_0:
 127                 /* Magic here: If we listen() and a new link dies before it
 128                    is accepted() it isn't 'dead' so doesn't get removed. */
 129                 if (sock_flag(sk, SOCK_DESTROY) ||
 130                     (sk->sk_state == TCP_LISTEN && sock_flag(sk, SOCK_DEAD))) {
 131                         bh_unlock_sock(sk);
 132                         rose_destroy_socket(sk);
 133                         sock_put(sk);
 134                         return;
 135                 }
 136                 break;
 137
 138         case ROSE_STATE_3:
 139                 /*
 140                  * Check for the state of the receive buffer.
 141                  */
 142                 if (atomic_read(&sk->sk_rmem_alloc) < (sk->sk_rcvbuf / 2) &&
 143                     (rose->condition & ROSE_COND_OWN_RX_BUSY)) {
 144                         rose->condition &= ~ROSE_COND_OWN_RX_BUSY;
 145                         rose->condition &= ~ROSE_COND_ACK_PENDING;
 146                         rose->vl         = rose->vr;
 147                         rose_write_internal(sk, ROSE_RR);
 148                         rose_stop_timer(sk);    /* HB */
 149                         break;
 150                 }
 151                 break;
 152         }
 153
 154         rose_start_heartbeat(sk);
 155         bh_unlock_sock(sk);
 156         sock_put(sk);
 157 }
 158
 159 static void rose_timer_expiry(struct timer_list *t)
 160 {
 161         struct rose_sock *rose = from_timer(rose, t, timer);
 162         struct sock *sk = &rose->sock;
 163
 164         bh_lock_sock(sk);
 165         switch (rose->state) {
 166         case ROSE_STATE_1:      /* T1 */
 167         case ROSE_STATE_4:      /* T2 */
 168                 rose_write_internal(sk, ROSE_CLEAR_REQUEST);
 169                 rose->state = ROSE_STATE_2;
 170                 rose_start_t3timer(sk);
 171                 break;
 172
 173         case ROSE_STATE_2:      /* T3 */
 174                 rose->neighbour->use--;
 175                 rose_disconnect(sk, ETIMEDOUT, -1, -1);
 176                 break;
 177
 178         case ROSE_STATE_3:      /* HB */
 179                 if (rose->condition & ROSE_COND_ACK_PENDING) {
 180                         rose->condition &= ~ROSE_COND_ACK_PENDING;
 181                         rose_enquiry_response(sk);
 182                 }
 183                 break;
 184         }
 185         bh_unlock_sock(sk);
 186         sock_put(sk);
 187 }
 188
 189 static void rose_idletimer_expiry(struct timer_list *t)
 190 {
 191         struct rose_sock *rose = from_timer(rose, t, idletimer);
 192         struct sock *sk = &rose->sock;
 193
 194         bh_lock_sock(sk);
 195         rose_clear_queues(sk);
 196
 197         rose_write_internal(sk, ROSE_CLEAR_REQUEST);
 198         rose_sk(sk)->state = ROSE_STATE_2;
 199
 200         rose_start_t3timer(sk);
 201
 202         sk->sk_state     = TCP_CLOSE;
 203         sk->sk_err       = 0;
 204         sk->sk_shutdown |= SEND_SHUTDOWN;
 205
 206         if (!sock_flag(sk, SOCK_DEAD)) {
 207                 sk->sk_state_change(sk);
 208                 sock_set_flag(sk, SOCK_DEAD);
 209         }
 210         bh_unlock_sock(sk);
 211         sock_put(sk);
 212 }